Variable thrust and reversing propeller



Sept. 13, 1949. J. B. JAMES VARIABLE THRUST AND REVERSING PROPELLER Filed June 14, 1946 Patented Sept. 13, 1949 OFFICE VARIABLE THRUST AND REVERSING PROPELLER Jerome B. James, Emigrant Gap, Calif.

Application June 14, 1946, Serial No. 676,727 4 Claims. (01. 170-16052) The present invention relates to marine propeller drives and is more particularly concerned with a propeller adjustable to perform the dual functions of forward and reverse drives.

The primary object of the invention is to provide a propeller of the character referred to which can be readily changed over from a forward thrust to a reverse thrust.

Another object of the invention is to provide a propeller of the character referred to which is controlled automatically as well as manually.

A further object of the invention is to provide a propeller with integral forward-thrust and reverse-thrust blades which are under selective control.

Still another object of the invention is to pro-- vide a double-duty propeller blade which is adjustable for the purpose of stowing one blade away when the other one is in use.

With the foregoing and other objects and advantages in view .the invention consists of the novel construction and arrangement of parts hereinafter described and claimed.

In the accompanying drawings illustrating the preferred embodiment of the invention;

Figure 1 is a side elevation of a propeller hub and blades constructed in accordance with the invention.

Figure 2 is a longitudinal section thereof.

Figure 3 is a transverse section of the hub on line 3-3 of Figure 1.

Like numerals, as used in the description and drawings, designate the same structural parts.

The body In of the propeller hub is tubular in general and open at the rear, where the closure is a screw cap II. This is provided with vents l2.

The propeller shaft I3 is tubular and preferably integral with the hub.

Two diametrically disposed rectangular apertures M are provided in the hub for reception of the bosses l5 of dual propellers. The bosses are mounted in said apertures to pivot on transverse pins I6.

Each propeller consists of two integral blades l1 and I8 positioned relatively at an angle of approximately 90. If desired, more than two propeller units may be employed, in which case additional recesses l4 and Ila will be provided.

The blade l1 designed for forward thrust, is longer in area than l8, and located rearwardly of the blade l8, which is designed for a reverse or forward thrust. Apertures H are constructed to allow the blades to be dropped down close to axial parallelism with the propeller shaft I3, so that whenever the blade I8 is not use it can be made to flush with the hub I0, as illustrated in Figure 1.

Projecting laterally from the bosses of the propellers and approximately at an angle of are lugs l9 with the outer edges curved to serve as cams which bear against-a cup-shaped member 20, which is axially reciprocable within the hub l0 and serves to contain one end of a coil spring 2:. The other end of the spring bears against the interior surface of the hub cap II.

A longitudinal control rod 22 is secured fast to the center of the closed end of member 20, and extends forwardly through the tubular propeller shaft l3 toa point of control, located as desired. The function of the rod 22 is'to drop either blade of the propeller as desired, and it may be operated by levers or other means, in the forward housing of the gear case, with controls in proximity to the motor head. As the closed end of member 20 is perpendicular to the axis of rotation the blades are caused to operate evenly and equally, thus eliminating a possible source of vibration. w 7

When the two forward-thrust blades are in operating position, they are perpendicular to the axis of rotation, thereby presenting maximum areaswith the water. Atthesame time the reverse thrust blades are flush with the surface of the hub 10, a recess Ma extending forwardly from aperture l4 for this purpose.

When the blade I8 is in operating position, the blade I! is lowered to close proximity with the surface of the hub.

Control of the cams on bosses I5 is attained in several ways. Two are here explained. The inner end of control rod 22 may be suitably linked directly to the cam shaped lugs l8 to allow shifting positively from maximum forward position to maximum reverse or to an intermediate position; or the cam construction hereinbefore described may be used. In the latter case action of the coil spring 2| tends to maintain the blades in reverse thrust position but the torque presented will cause the blades to shift into forward thrust position, due to centrifugal force and the reater thrust area of the blades I 1. Such action becomes automatic by control of the propeller speed but can be controlled by use of control rod 22.

It will thus be obvious that the propeller blades can be held in reverse or in an intermediate position for reduced boat speed.

As different embodiments may be made of this inventive concept and modifications may be made in the embodiment hereinbefore shown and described, it will be understood that the matter herein is to be interpreted as illustrative merely, and not in a limiting sense.

What I claim is:

1. A propeller comprising a tubular hub, two integral blades having a common boss with a cam shoulder, said boss being pivotally mounted in said hub, said blades being set relatively to each other at snbstamtim'aright angle and; with relative pitches' to pro'duce in one a: forward thrusting action and in the other areverse thrusting action, an axially reciprocable rod to operate sai'el cam to pivot said blades alternatelyeoutrof op erative position, and resilient means to produce.

axial tension on said operating rod. v

2. A propeller comprising a tubular hub; a tubular powered shaft secured; to the hub apiurality of units comprising two integral blades having a common boss with a, cam shorrldei -sa-id hub being provided with recesses to allow the blade-5 2110 "be alternately-1nd; in substantial parallelism with the hub axis, said boss being pivotally mounted in'xsaidr hum/said blades being set: relatively to each other at substantially a right angle andgw-itlsr relativexpitches to produce iii-one a iorwardthrustingmotion and inthe other; 2; reverse thrustingcmotiiongla reciprocable cup shaped member eonitazinedimsaid hub a: coil spring"containerhinwsaidmember and positioned to exert tensiorr thereon, :asrenmvable cap with vents-' forrthe nose Q'fEthEZhRbPtGNBJHOWfiCBBSS to said memberamtspring and a l'ongitudinal controls. rod securecbtozthet base? of. said cup-shapedmember and passingtlrrmlghthe: propeller shaft, said member abutting: said; shoulder and actuating same when iseoperated to: pivot said blades alternateiy outroii operative: position.

3 Aapropeilerr comprising arotatable hub, a pair of blades connected movementitogether; saidrpair cit-blades havinga-rprodecting lug;,a common pivotifo-rsaidpair oibiadesiextemh'ngi trans verselysaid? lamb, said-blades being: oppositely pitched to exert forward and rearward-thrusts, respectively;and-smug, spacedfrom each other, said hub provided: wit-1r means for causing saidtpairrof blades tonormally occupy a position in which one-bf blades lies along 4 V 7 said hub in an inoperative position and the other blade extends radially from the hub in an opera tive position, and operating means for moving said pair of blades from said normal position to a position in which said one blade, extends a spring means actingupon said lug in one direction, and other means operai ti'ng, uporrisaid spring meansin'anopposite direction.

V 4. A propeller comprising a rotatable hub, a pair of blades connected for movement together, said. pair of blades having a projecting lug, a common pivot for said pair of blades extending transversely of said hub, said'blades being oppositely' pitched to exert forward and rearward thrusts, respectively, and being angularly spaced from each other, said hub being provided with means for causing said pair of blades to normally occupy a position in which one of the blades lies along said chub insane inoperativeposition and the other blade extends radially,fromthexhub:

an operati-Veposition, and: operating. means for' directionand a longitudinally movableselement I extending axially throughzgsaidx hub operating 7 upon said spring means irr opposite, direction;

' REFERENCES orrso The following references are of record irr thefl fiie'of atent; 'UNIIEDLSIA'IESHPATENTS Number Date. I 

